[3B06-08] Nuclear Fusion Engineering (First wall and Divertor)

[3B06] Evaluation of the applicability of directional solidification for the purification of molten salt Flinak

*Hiroki Shishido¹, Toshiyuki Onodera², Keitaro Hitomi¹, Noritaka Yusa¹, Hidetoshi Hashizume¹ (1. Tohoku Univ., 2. Tohoku Institute of Technology)

Keywords:Liquid blanket, Molten salt, Purification, Directional solidification

Molten salt Flinabe (LiF–NaF–BeF₂) has been proposed as the first candidate material for a liquid blanket system in FFHR-d1. A chemical purification method for molten fluorides has been employed using HF and H₂ gases. This method, however, requires expenditure on special equipment to handle the HF gas because it is extremely toxic. The objective of this study is to evaluate the applicability of directional solidification for the purification of molten salts. In the directional solidification method, molten sample is translated slowly into a cooler section and impurities are segregated from the sample. The method is expected to make the purification process easy and low-cost. This study applies the method to purify Flinak (LiF–NaF–KF) as a first step towards Flinabe purification because it is easily handled. The applicability of the method are evaluated by analyzing the impurities of the samples using ICP-MS.